Microwave heating applications of fluidized beds: High-purity silicon production

The use of microwaves as an alternative energy source to heat fluidized bed reactors was investigated. The cavity resonance technique based on frequency tuning was utilized to measure the dielectric properties of materials studied for fluidized bed heating as a function of temperature.;Microwave tuning behavior of the experimental fluidized bed reactor was also theoretically and experimentally investigated as a function of dielectric properties and dielectric bed height in the reactor. Lower order mode resonance frequencies were computed and verified experimentally. The electric field distribution for the dominant mode in the reactor was calculated for the purpose of obtaining information about temperature distribution in the reactor.;The fluidized bed reactor existing prior to this research was modified to accommodate microwave entry from the bottom of reactor. Microwave heated fluidized bed reactor experiments were conducted with silicon, alumina and cobalt/alumina catalyst. The alumina bed was heated to temperatures above 1000;Microwave heating of silicon in the fluidized bed reactor was demonstrated at temperatures above 1250;The dielectric properties of 10 silicon samples of various sizes from two different sources were measured as a function of temperature in the range 23-650...